Improvement in steam-engines



UNITED STATES PATENT OEEICEe GEO. I. WASHBURN, OF WORCESTER, MASSACHUSETTS.

IMPROVEMENT IN STEAM-ENGINES.

Specification forming part of Letters Patent No. 57,228, dated August 14, 1866.

To all whom it may concern: u

Be it known that I, GEORGE I. WAsHBURN, of the city and county of Worcester, and State of Massachusetts, have made new and useful Improvements in Steam-Engines; and I do hereby declare the following to be a full, clear, and exact description of the nature, construction, and operation of the same, suflicient to enable one skilled in the art to which it appertains to construct and use the same, reference being had to the accom pan yin g drawings, which are made part of this specilication, and in which similar letters refer to corresponding parts in the different figures.

Figure l is a vertical central section. Fig. 2 is an elevation. Fig. 3 is a section on the line a* 1fc Fig. l. Fig. 4 shows an arrangement in which the valves are operated by a rod, y, which slips inside of the piston-rod a. The pistons are fastened to the outer or piston rod, which forms a sleeve around the valve-rod, the motion of the valves being kept ahead of the pistons, so as to give lead if required, the relative points of attachment of' the valverod and piston-rod in the circle of revolution being adapted to the requirements of the case. Figs. 5 and 6 show an arrangement of three cylinders, the three piston-rods being attached to cranks set at angles of one hundred and twenty degrees with each other on the same shaft. Figs. 7 shows an arrangement in which the valves are made to slip upon the piston-rods, which permits the use ot' shorter cylinders.

The invention consists in the arrangement of the effective spaces of the two cylinders so that they receive their steam through ports directly through the partition between the cylinders, and avoid long connecting-passages. The effective spaces of one cylinder are at the ends, while the effective spaces of the other cylinder are near the center, and consequently the passages are very much shortened, and become, in fact, mere ports. The valves in the respective cylinders, in passing the ports which open into the elfective spaces, are thus as near as possible to the said spaces, and long connecting-passages are avoided.

The above-described arrangement of the effective spaces involves a suitable location of ports, and also the use of two devices, con- U'sisting, in the one case, of two singleacting pistons, between which are located two valves, all being fast upon the same piston rod or stem, and in the other case of two valves, between which are located two single-acting pistons, which are separated by a diaphragm or partition, through which works freely in a longitudinal direction the piston-rod to which the said valves and pistons are attached.

Were the two cylinders the counterparts of each other, having the effective spaces similarly located-that is to say, with the effective spaces ot each cylinder at the ends, or the reverse at the centerit would necessitate a corresponding similarity in the location of the valves and pistons, which would require greater length of steam-passages between those extremities of the port over which the valves moved and those leading into the effective spaces.

In the drawings, A B are two cylinders, having in them piston-rods c b, respectively. On the rod a are the single-acting pistons c c and valves d d', the pistons being nearer to the center of the cylinder, which is occupied by the diaphragm or partition e, while the valves d d are nearer the ends or heads f f. On the pistonrod b are the single-acting pistons g g and valves h h', the pistons being nearer to the heads 'i i and the valves occupying the central position. L

The ports for the passage of steam into and from the cylinder A are shown at j j and the exhaust-ports at la la. When the valve t is on one side of the port j it is admitting steam into the upper elfective space of the cylinder A from the feed-pipe I, the steam passing between the valves li It', and when the valve h is on the other side of the said port j the exhaust-steam passes from the said space, between the pistou g and valve h, toward the exhaust pipe m through port 7c.

The action of the valve h is the counterpart of the above.

The ports for the passage of steam into and from the cylinder B are shown at u n and the cxhaust-ports at 0 o. When the valve d is on one side of the port a it is admitting steam in to the upper effective space of the cylinder B from the feed-pipe p, the steam passin g between the valve d and piston c, and when the valve d is on the other side of the said port a the exhaust-steam passes from the said effective space between the valve d and head f of the cylinder A.

The action of the valve 0lk is the counterpart of the above.

Above the cylinders are standards C, which support the main shaft D and ily-wheels E. The shaft is provided with two cranks set at relative angle ot' ninety degrees. The rods 1' r connect the cranks to the cross-heads s s, Whose slides are guided by the Ways t ton the standards O.

The feed and exhaust-steam pipes are connected in any suitable manner and in the appropriate relative positions.

When the double crank is used the relative positions of the pistons and the valves which govern the action of the steam upon the said pistons will be determined by the angle of the cranks, which will ordinarily be as shownthat is, at right angles with each other; but when the engine is used as a valve, a pump, or for operating stamp or other Works requiring no rotary motion,the length of the stroke will be determined by the nature of the workas, for instance, in stamping or forging-or by the length of the cylinder in some other cases. h y

When I use three or more cylinders, as in Figs. 5 and 6, it may be desirable to so arrange cranks that the momentum of the moving pistons Will be counterbalanced one by another,

the relation between a given valve and its piston remaining as above explained.

When four pistons are used the cranks will be ninety degrees apart, two adjacent cranks being attached to two coacting pistons and -the other two to corresponding coacting pismove over but a small portionl'ot' the length ofthe cylinder instead of having a motion longitudinally of the cylinder equal to that of the pistons. l y

The valves of a given cylinder are attached together, and may thusf'orm aspool, which slips as a sleeve upon the piston-rod in cylinder B, Fig. 7; or they may be attached by stayrods u, as in the cylinder A, Fig. 7.

Having described my invention, what I claim therein as new, and desire to secure by Letters Patent, is-

1. The cylinderA, constructed, as described, with a diaphragm or partition at its central portion, traversed by the piston-rod and combined with the pistons, as specified.

2. The combina-tion of t-liecylinders A B, constructed and operating as described.

GEO. l. WASHBURN.

Witnesses:

EDWARD H. KNIGHT, ALEXR. A. C. KLAUCKE. 

